Power dissipation, especially for large integrated circuits, tends to generate a significant amount of heat, which may raise the junction temperature of the integrated circuit above safe reliability limits (e.g., above process limits). Consequently, it is important to monitor and maintain the temperature of the integrated circuit to within safe operating limits to prevent failure or a noticeable reduction in device lifetime.
A common approach to monitoring integrated circuit junction temperature uses an on-chip temperature sensing diode connected between two input/output pins of the integrated circuit. A separate integrated circuit then monitors the voltage difference between the two pins. Thus this approach requires a separate integrated circuit on the printed circuit board to receive and translate the diode voltage and/or current (e.g., using a delta-sigma analog-to-digital converter) into a corresponding temperature value, which may be complex and costly in terms of printed circuit board space, interface limitations, assembly costs, and/or power requirements.
As a result, there is a need for improved techniques for measuring the temperature of an integrated circuit.